The laws of static friction are,
- When two surfaces are in contact , the frictional force is always tangential to contacting surfaces in a direction opposite to that in which the body tends to move.
- The limiting force of static friction is directly proportional to normal reaction between two surfaces in contact.
- The force of static friction depends on nature and materials of surface.
- The coefficient of static friction is independent of the area and shape of the contacting surfaces.
The formula for law of static friction is given as,
FS = µs N ——— where FS=Force of static friction, µs= coefficient of static friction and N=Normal force
The formula for coefficient of static friction is given as,
µs = FS / N